Siren



E. W. ERICK.

SIREN.

APPLICATION FILED 0c.14, 1921.

Patented Sept. 12, 1922.

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Patented Sept. 12, 1922.

so STATES 1 EMIL W. ERICK, 0F CANBY, MINNESOTA.

SIREN.

Application filed December 14, 1921. Serial No. 522,316.

To all whom it may concern:

Be it known that I, EMIL WV. ERICK, a

citizen of the United States, residing at- Canby, in the county of Yellow Medicine and State of Minnesota, have invented certain new and useful Improvements in Sirens, of which the following is a specification.

This invention relates to sirens of the drum type, and more particularly to sirens adapted for use in communities, or small towns for producing fire alarm signals and signals for other emergencies, an object of the invention being the provision of a structure in a siren, which will render the sound far reaching in all directions, as distinguished from sirens, wherein the sound volume is directed in a specific direction by the use of a funnel or horn. In rural districts, or in the open country where the populace is widely distributed, it is highly desirable to have signal means, whereby the sounds may be disseminated in all directions excepting upwards, s01 that the device, in a hilly country may be mounted on an eminence, and radiate sound waves in all directions.

Another object of the invention is to provide a novel construction in a siren,

whereby the rotor or impeller casing, to be hereinafter termed a stator, which is customarily made of cast iron and bored in a lathe, may be made of thin sheet metal whereby the wind is more readily and easily cut, thereby facilitating the production of a large sound volume which is not possible when using cast iron casings, inasmuch as the wall of the casing cannot be less than one quarter of an inch in thickness in casings of 10 or 12 inches in diameter, as cast iron will not run thinner than that, Thus, a thick edge is presented to the escaping wind, which seriously impedes the production of sound, and requires greater driving power. Owing to my improved structure, I am enabled to use very thin sheet metal, which can easily and conveniently be made to conform to the rotor diameter, and which may be cheaply manufactured, and easily re-placed.

A further object of my invention is the provision of a siren, which may be safely mounted in unprotected places, such as on buildings and towers, the structure being designed to protect against the elements such as snow and sleet and to prevent birds building nests therein, so that the device requires but little attention.

Other objects of the invention will appear throughout the specification, the invention consisting in the construction, combination and arrangement of parts hereinafter described and claimed.

In the drawings forming part of the specification Figure 1, is a perspective view, drawn to a reduced scale, of a siren embodying my invention.

Figure2, is a vertical sectional view on line 22 of Figure 1.

Figure 3, is a sectional view on line 33 of Figure 2.

Figure 4C, is a perspective view of the rotor or impeller casing.

Figure 5, is a fragmentary perspective view of the rotor, a fragment of the casing being shown, and

.Figure 6, is a plan view of the clamping ring whereby the rotor casing or stator is held positioned.

In the drawings I have shown my improved siren connected directly, to a vertically disposed electric motor, but any otherv source of power may be substituted, it not being thought necessary to describe the motor shown.

A designates the base, B the housin surrounding the ielectric motor, and 6 the siren. The base and housing may be of any suitable shape, the base being adapted to be secured in position as by means of bolts in the bolt holes 1.

Rotatably supported in the end bearing 2, in the base, is the driven shaft 3, which latter in the siren shown, forms part of the electric motor I) encased in the housing B, said motor being indicated by dotted lines in Figure 2. The conducting wires 4, are intended to be connected with a source of current, a tripple wire double throw switch 5, being provided to thereby control the motor, said switch being shown diagrammatically. By the use of the double throw switch, the motor may be abruptly stopped and started at will.

The siren 0, comprises a preferably circular horizontally disposed supporting plate 6, here shown secured to the top of the housing B, and having a vertical bearing 7, wherein is journaled the shaft 3, the latter extending with a part 3' of reduced diameter, beyond said bearing, and carrying rigidly mounted on said reduced part, the rotor 8.

As shown, the rotor is driven against the shoulder formed by said reduced part, and held )ositioned on the latter, by the lock nut 9. rojecting from the upper flat surface of the supporting plate, is the annular head 10 concentric with the shaft, and having a shallow perpendicular annular inner wall 11. the inner diameter of the bead being slightly in excess of the outer diameter of the rotor. Resting with its lower circular edge on the supporting plate, and removably fitting the inner diameter of the bead, and surrounding the rotor in amannor to permit the latter to freely rotate therein, is the circular thin sheet metal rotor casing or stator 12, best shown in Figure 4 of the drawings. This stator or casing, is of uniform diameter and height, and extends slightly above the top of the rotor, and is perforated circumferentially preferably at regular intervals with a plurality of elongated, vertically disposed, rectangular ports 13, each preferably spanned centrally by a horizontal tie member 14, of relatively small cross section for a purpose hereinafter to be explained.

This casing is cheap of manufacture, in that it may be'struck out of relatively thin sheet metal such as #20 gauge, in strip form. and spot welded at a vertical seam as at a, Figure 4;. Thus, the stator is made of m-ctal too thin to maintain a true circular contour without additional support.

Resting upon the top circular edge of the stator and extending surroundingly beyond the outside thereof, and having a shallow annular recess 15 in the underside to fit over said edge, is the flat retaining ring 16, havlllg suitable bolt holes 17, in ,vertlcal alinement with similar bolt holes 18, in the supporting plate 6, said holes adapted to receive bolts 19 whereby the stator may be firmly bolted in operative position around the rotor. The ring 16 bolts 19 and the bead 10 may he termed fastening means engageable by a rotor to hold the latter int-rue circular form.

The rotor comprises a spider having uniformly spaced radial arms, each arm carrying at its outer extremity, a vertically disposed vane 20, adapted to overlap the ends of the ports 13, in the stator.

The vanes are preferably V-shaped in cross section. the outer faces of the vanes being of uniform width and constituting, collectively, the outer cylindrical face of'uniform diameter, of the rotor. The spaces between the vanes preferably egister with the ports of the stator. As the speed of the rotor is' accelerated, the sound increases'in volume, and the pitch varies accordingly, the use of the double throw switch enabling the motor to be controlled at will to produce 2.

definite predetermined signal which may consist of a plurality of blasts as the case may be.

By constructing the stator of thin sheet metal, the relatively sharp cutting edges of the ports 13, cleave the air so keenly, as to roduce sound waves of far reaching pene tration. I have used heavy cast and thin plate stators, in the same siren, under similar conditions, and have lOUIld that the thin plate stator produced sound that could be heard at an appreciably greater distance than that produced by the use of a heavy, thick non-vibrating stator. The thin stator imparts a characteristic timbre or clang tint to the sound which is due to the vibration set up in the thin knife-like cutting edges of the ports. in a manner akin to the Well known principle. whereby a thin sheet of paper or a card. may be vibrated to produce sound, by placing it edgewise transversely of the lips and blowing thereagainst.

In addition to this important advantage of securing a more far reaching sound of a pleasing timbre. by the use of a thin sheet metal stator, the I10"9l feature of providing the cross tie members 14 in the ports, of the latter,.enables the construction of stators of any size. Without these tie members, the bands of metal separating the ports, should they be slightly longitudinally bowed, will interfere with the vanes of the rotor; the cross ties operating as guards or guides whereby butt contact between the vertical edges of the vanes and ports, is averted.

Surrounding, spacedly. the sound producing devices. and extending outwardly and upwardly from the supporting plate 6, is the screen enclosure 21. This screen wall which may be any kind of open work structure with uniformly distributed openings is disposed at a suitable angle with respect to the vertical, to cast off hail and rain and supports the circular conic roof or hood 22, formed with a surrounding downturned overhanging drip flange 23. whereby the siren is effectively protected against the elements and invasion of birds and, insects.

A. further object of using a screen wall, that is. a protective wall consisting solely of wires which are uniformly interwoven, or disposed relative to each other, to form a perforated wall which is uniformly pene trable by sound throughout its entire area. so that the volume of sound waves passing through the screen wall meet with a uniform resistance to avoid periodic deflection in the sound, as distinguished from a screen wall which has intervening uprights or supporting bars or other obstruction to offer a variable resistance.

For the purpose of deflecting the sound. to cause it to travel laterally in all directions, I provide a circular deflector, 24, the deflecting under-surface thereof, radiating uniformly upwardly and outwardly from a point in the axis of rotation of the rotor, located preferably below the top thereof. The deflecting surface is preferably concaved, and may be of thereby enabling the de ector to dip deeply into the interior of the rotor, and still secure ample passage way between the deflector and the retaining ring 16, as at b.

The rotor shaft may be connected by gear \train with manually operable actuating mechanism, and the supporting plate 6, housing B and base A, may be termed a supporting frame. As the walls of the stator are of uniform curvature, a relatively firm downward pressure may be applied by the bolts 19 before a tendency to buckle is arrived at thereby enabling metal asthin as #20 gauge to be used.

I claim: 1. In a siren, the combination of a frame, a rotor revoluble on said frame, fastening means engageable by a stator for fastening the latter in operative position to the frame around the rotor, and a round stator having a plurality of ports in its peripheral wall and consisting solely of an open ended relatively thin sheet metal shell, the ported wall of the shell being so thin as to be incapable of maintaining the shell in true circular form without additional support, said shell engaging with said fastening means to be thereby fastened and supported in true circular form to permit said rotor to freely rotate therein.

2. In a siren, in combination, a frame, a rotor open at the top revoluble on said frame, fastening means, a round casing made of thin sheet metal and open at the top and having a plurality of ports in its peripheral wall, said casing engaging with said fastening means to be thereby fastened, in .true circular form to the frame around said rotor, said fastening means including a garabolic curvature,

3. A siren, of the class described, comprising a vertically disposed driven shaft, a hollow rotor open at the top rigid on the shaft, a ported stator surrounding the rotor in a manner to permitthe latter to freely rotate therein, and a dished deflector plate concentrically positioned in spaced relation above the surrounding upper edge of the rotor but dipping centrally an appreciable distance below said upper edge for directing the sound late-rally.

4. In a siren of the class described, in combination a vertically disposed siren, having a relatively large top sound discharge opening, and a horizontal deflector member above the .siren in the path of the sound emitted from said top: discharge opening, said deflector member constructed to dip centrally into said discharge opening for the purpose set forth;

5.,In a siren of the class described, in combination, a siren of the drum type including a supporting frame and constructed to direct the sound vertically, said siren including a stator and a rotor, and means in the path of the sound for deflecting the latter symmetrically laterally in all directions, said means consisting of a circular deflector plate shaped like an inverted cone and positioned centrally above said stator and rotor in the path of the sound to deflect it laterally, and a protecting screen shaped like an inverted frustrum of a cone surrounding said rotor and stator, its lower surrounding edge secured to said frame and its upper surrounding edge secured to said deflector plate to serve as a support therefor.

In testimony whereof I aflix my signature.

EMIL W. ERICK. 

